Bolt assembly for a firearm



1953 E. c. LEE

BOLT ASSEMBLY FOR A FIREARM 2 SheetsSheei 1 Filed April 16. 1954 INVENTOR. EDWARD C.LEE

A TTOIZNEYS Dec. 9, 1958 LEE 2,863,246

BOLT ASSEMBLY FOR A FIREARM Filed April 16, 1954 2 Sheets-Sheet 2 IN V EN TOR. EDWARD C. LEE

276 MQQM A TTOENEXS nited States Patent Ofifire Fatented Dec. 9, 1958 BOLT ASSEMBLY FOR A FIREARM Edward C. Lee, Detroit, Mich., assignor to Ithaca Gun Company, Incorporated, Ithaca, N. Y.

Application April 16, 1954, Serial No. 423,553

1 Claim. (Cl. 42-16) This invention relates to a bolt assembly for a firearm and, more particularly, to a bolt or breech block containing a novel type of locking block therein for use in firearms of the automatic and semi-automatic type.

In the ordinary type of shot gun, such as that disclosed by Browning U. S. Patent No. 689,283 dated December 17, 1901, it will be noted that the bolt or breech block assembly is provided with a body portion, an operating slide and a locking block connected to the spring action link assembly and a firing pin extending through the body portion. The locking block assembly, as used therein and in other types of guns, is complicated and expensive to machine in that it and the body portion must be provided with a combined, machined pivot action whereby the locking block has an outwardly extending circulater rib or track section adapted to fit in a correspondingly circular recessed portion in the body of the breech or bolt assembly. In addition, the circular track of the locking block must be separately and accurately machined and the corresponding circular recess in the body must be separately trepanned and the bolt properly fitted. It is apparent, therefore, that a construction of this type requires considerable machining in contrast to the invention hereinafter described.

With the above in view, it is an object of my invention to provide a breech block or bolt assembly which can be economically and relatively more easily made for use for any type of firearm of the automatic or semiautomatic type.

Still another object of my invention is to provide a breech block having an easily connectible locking block of relatively simple construction.

Other objects and features of my invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a fragmental, longitudinal, sectional view of a firearm embodying a preferred type of my invention;

Fig. 2 is a detailed, enlarged, longitudinal, sectional view of my invention, separate from the firearm and taken on line 22 of Fig. 3;

Fig. 3 is a front end view of Fig. 2;

Fig. 4 is a fragmental, sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a side elevation of Fig. 2; and

Fig. 6 is a bottom plan view showing a breech block embodying my invention but having the locking block removed therefrom.

Referring now particularly to the drawings embodying a preferred type of my invention and wherein like reference characters denote like parts throughout, it will be noted that agun 10 is provided with a barrel 11 and a magazine tube 12, a receiver 13, and a stock 14. Said receiver 13 is provided with a trigger mechanism assembly l5 and a bolt or breech block assembly 16 which will be hereinafter more fully described.

In said bolt or breech block assembly 16, it will be noted that the body or breech portion 16' is adapted to slide in opposed grooves not shown in the inside face of the receiver. Rearward sliding action of the block assembly is accomplished by the recoil forces resulting from the explosion of a shell in the gun chamber 18 of the barrel 11 and in a forward direction from the recoil spring 17 for the initial start of the movement and the action spring 40 through the link 19 for the completion of the same. The link 19 is pivotally connected to the under, rear part of a locking block 20 in the body 16. Said block 20 is movable up and down around its pivot 21 by means of said link 19. Said block body '16, as noted, is longitudinally recessed to accommodate said locking block 20 to permit free movement of the same in the body 16'. The body portion 16' has an upwardly extending rear portion 22 which is horizontally and circularly or arcuately recessed as shown at 23 forming a resting support as hereinafter will be described. The block 20, as noted, is provided with a correspondingly outwardly projected and rounded portion 23a to fit in said recess at 23 and is recessed forming a bifurcated lower portion for the end of link 19. The rounded portion 23a, with the recess, forms a bearing pivot for the locking block 20 to permit its easy up and down movement in the body portion 16. Furthermore said rear portion 22 of breech block 16 has an overlap 24 to prevent the block 20 from dropping out of the body 16' when the locking block drops down into the recess of the body 16 or from being pushed out of the body when the link 19 forces the locking block upward. Said body 16' is recessed so as to accommodate firing pin 25 also which extends through the body but is held in position therein by means of a cross pin member 26 extending horizontally through the rear portion of said body. It will be noted also that said firing pin 25 is provided with a tension spring 27 at its forward end, as shown, which tension spring is partly housed in the forward part of the body portion of the breech block 16. The bolt or breech assembly is further provided at its lower portion with a latch 28 pivoted to the forward part of the body portion. Latch 28 is adapted, at its rear end 29, in conjunction with link 19, to keep the locking block upward whereby the tongue 39 of said locking block 20 fits in the opening 31 in the barrel extension 32 of the gun and engages the rear of the opening 31.

Furthermore, the forward part 33 of said latch 28 is adapted to be pressed downwardly by means of a spring member 34 housed in a vertical recess or hole 35 of the body of said breech block. Said latch, at its forward end 33, acts as a stop for a shell as it is forced out of the magazine 12. It is to be noted that the latch shown herein is not the conventional latch for this system and is used as an illustration.

In Fig. 5 I show details of the forward part of the breech block which is provided with an extractor 39 operated by a plunger 36 which is under the action of a spring 37 in a recess 38 in said breech.

From the foregoing description, taken in connection with the accompanying drawings, it will be noted that I provide a breech block assembly 16 wherein the locking block, at its rearwardly extending portion, bears against the breech block in the circular recess area 23 when the block is pivoting. Also, the upwardly extending forward portion 30 of the locking block readily hooks onto the barrel extension at the opening thereof so as to bring the barrel rearwardly after each explosion of a shell in the firing chamber 18 of said gun.

A bolt or breech block assembly of the type described and illustrated herein can be readily connected or disconnected from the breech block. Also, it prevents freez ing and permits accurate and non-obstructive pivotal movement of the locking block in the breech or bolt assembly. The pivotal action or movement at the end of the locking block, in contrast with the type of circular track movement of the ordinary type of locking block, is simple and very eifective. block assembly, taken down, can be readily cleaned since the inner walls of the recessed portion of'the body 1'6" are smooth and free of any trepanning or inside cuts.

It is apparent, therefore, that the rear forces are cen While a preferred embodiment of my invention has been described and illustrated herein, it will be noted that various modifications as to form, structure and arrangement, and use of parts may be made without departing from the spirit and scope of my invention as claimed.

I claim:

In a recoil operated firearm having a receiver, a barrel with a magazine tube, and a stock, the improvement comprising a barrel extension having an opening therein, said extension being slidable into the receiver, a breech block'slidable longitudinally of the barrel in the receiver, said breech block having a longitudinally slotted bottom In addition, the.

cularly recessed portion, the latter portion forming a pivot for thelocking block, said locking block having a rearward circularly arcuate projection pivoted in saidrecessed portion about a transverse axis thereat and a forward arcuate portion slidable on the arcuate front Wall of the breech block in an arc concentric with said axis, said overlapping portion of the breech block being adapted to prevent dropping out of the locking block, said locking block having a tongue at its upper forward portion adapted to fit in the opening of the barrel extension of the firearm and engage the rear portion thereof,. a firing pin extending through the breech block, and a transverse pin through said breech block for said firing pin.

References Cited in the file of this patent UNITED STATES PATENTS 577,281 Browning Feb. 16, 1897 1,702,984 Shelrnan a Feb. 19, 1929 1,852,411- Henry Apr. 5, 1932 2,418,946 LoOmis Apr. 15, 1947 2,480,074 Browning Aug. 23, 1949 2,714,334 Harvey Aug. 2, 1955 2,715,356 Fiorini -1 Aug. 16, 1955 

